(a) Technical Field of the Invention
The present invention relates to an improved structure of a resistive bubble lamp, and in particular, to a bubble lamp employing a vacuum glass tube containing a low boiling point liquid, CH2Cl2. The present invention employs LED to provide colorful light emissions and heat-generating resistive components to provide heat to produce decorative bubbles from the low boiling point liquid.
(b) Description of the Prior Art
In everyday life, decorative lamps are normally used at night for the purpose of producing aesthetic light effects. For example, a bubble lamp is such a decorative night lamp. Generally, the bubble lamp comprises a vacuum glass tube sealed at the top end. The glass tube is filled with a low boiling point liquid, CH2Cl2, and the bottom end of the glass tube is sealed with a hot light bulb. The top end of the light bulb is tightly in contact with the bottom end of the glass tube so that when the light bulb is electrically connected to a power source, the heat from the light bulb received by the bottom portion of the glass tube will be directly distributed to the liquid within the glass tube, and the heat will instantaneously cause the liquid to reach its low boiling point to produce bubbles within the glass tube. The basic circuit for the prior art bubble lamp is located inside the night light. When an external AC power source is connected through the RC oscillator and bridge transformer, a DC current is provided to the hot light bulb and causes it to light. Alternatively, a DC power source may be applied instead to cause the light bulb to light.
With respect to the above basic night lamp, the light bulb normally uses tungsten which has the drawbacks of low efficiency, high current consumption, short life and high working temperature. Moreover, the color of the light bulb is monochromatic, which only allows gradations of brightness. When the light bulb is used as night lamp light bulb, due to the short life of the light bulb, the efficiency and life of the night lamp are adversely affected. Therefore, the longevity of the light bulb needs further improvement. Further, the light effect generated by the monochromatic light from the light bulb is quite monotonous. In view of the above, there is room for improvement with respect to the light bulb employed in the decorative night lamp.
As a result of rapid development in the materials for use in electronic industries, more durable, portable, and high-efficient LED light bulbs will be available in the future. LED is a light-emitting element made from semiconductor. When current passes through LED, this electronic element will light. The material is from group III-V of the periodic table, for instance, gallium phosphate and gallium arsenate. The light emission is due to conversion of electric energy into light. That is, the semiconductor compound is applied with a current so that electrons and electron holes are combined, and the excessive energy is released in the form of light, thus creating light emission. This is considered as cold light and the life of the LED can be as long as hundreds of thousands of hours. Further, LED is characterized in no idle time, short response time (about 10−9 second), small volume, low current consumption, low pollution and availability of a plurality of applicable variations in night lamps. If LED is employed in a night lamp together with a bubble light bulb, a more aesthetic lamp with colorful light effects is obtained. However, the working temperature of LED is low and if LED is combined at the bottom end of the bubble lamp, the liquid in the vacuum glass tube of the bubble lamp cannot produce bubbles for decorative purposes.
In view of the above, it is an object of the present invention to provide a resistive bubble lamp structure, which can generate bubbles from the low boiling point liquid as decoration and which is characterized in long operating life, variations in lighting patterns and frequencies, etc. The present invention is expected to be welcomed by consumers.